Problem with installing SQL Server 2005

When I'm installing SQL Server 2005 Express Edition (but not only, error was also in Enterprise Edition 2005) there is an error. Everything is fine but on the end SQL Instalation cannot start SQL Service.
Does someone know how to solve this problem?
I'm installing SQL CTp 2005 with the newest .NET 2.0
Help!!What is the error you are seeing?

Dan
http://blogs.msdn.com/dtjones/|||Something like that: "Installer cannot start SQL Service" and everything is unistalling.